I was excited to gift my son with this pan and he was equally happy to receive it. He knows how to cook. However after his first encounter, the sides seem to be ruined on the inside. It’s left with black spots along the sides. The actual flat part to cook on, got cleaned very well but I don’t know what happened to the rest of the pan.  Very sad. This happened to both of our pots. I’m unsure what is the guarantee on this.